U.S. Pat. No. 4,910,402 describes various forms of apparatus wherein a static or dynamic drop of a liquid is formed suspended from the ends of a pair of light guides so that light can be directed into the drop from one light guide and collected in the other light guide (the term “light” is intended herein to include UV and IR as well as visible light). This allows many different types of measurement to be made on the liquid, as described in that patent.
The part of the apparatus near the lower ends of the two light guides, i.e. where the drop is formed, is referred to as a tensiographic drophead. In FIG. 3 of U.S. Pat. No. 4,910,402 the drophead is shown as a simple glass cylinder within which the light guides are secured in their desired relative positions by embedding them in epoxy resin. Although effective at the time, and still suitable for many measurements, there is a need for an improved drophead which will allow greater accuracy and reproducibility of results.